The prior art bed elevator is described in U.S. Pat. No. 2,933,850 issued April, 1960 to Martin. Martin discloses a stand with a shallow upper surface that can be raised endlessly by stacking similar units without regard to the effect of lateral force. The structure disclosed in this patent does not resist a horizontal impact force as would occur when moving the bed, which would cause the stand to topple. Related patents include:
U.S. Pat. No. 3,795,925, issued Mar. 12, 1974 PA0 U.S. Pat. No. 1,670,601, issued May 22, 1928, PA0 U.S. Pat. No. 2,067,515, issued Jan. 12, 1937, PA0 U.S. Pat. No. 2,072,791, issued Mar. 2, 1937, PA0 U.S. Pat. No. 2,147,538, issued Feb. 14, 1939, PA0 U.S. Pat. No. 2,599,723, issued Jun. 10, 1952, PA0 U.S. Pat. No. 3,178,146, issued Apr. 13, 1965, PA0 U.S. Pat. No. 3,310,289, issued Mar. 21, 1967, and PA0 U.S. Pat. No. 4,312,088, issued Jan. 26, 1982. PA0 U.S. Pat. No. 4,312,088, issued January 1982, PA0 U.S. Pat. No. 575,806, issued January 1897, PA0 U.S. Pat. No. 2,633,898, issued April 1953, PA0 U.S. Pat. No. 2,750,709, issued June 1956, PA0 U.S. Pat. No. 2,893,164, issued July 1959, and PA0 U.S. Pat. No. 3,795,425, issued March 1974.
Other related patents, which were cited in the above-mentioned basic patents, include:
The prior art bed elevator includes a bed which has a frame with legs, with a pair of elevator stands, each stand having a base portion for resting on the floor and having an upper portion for supporting the bed frame.
As indicated above a major problem with the prior art bed elevator is that a horizontal impact force which is accidently or intentionally applied to the bed in a longitudinal direction causes a moment on each stand that causes the stand to topple.
The foregoing and other objects, features and the advantages of the invention will be apparent from the following description of the preferred embodiment of the invention as illustrated in the accompanying drawings.